linux-toradex.git/drivers/clocksource/mips-gic-timer.c, branch v4.11

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-25T22:30:04+00:00

Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t

clocksource: Use a plain u64 instead of cycle_t

2016-12-25T10:04:12+00:00

There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: John Stultz

cpu/hotplug: Cleanup state names

2016-12-25T09:47:44+00:00

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Sebastian Siewior 
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner

clocksource/mips-gic-timer: Stop checking cpu_has_counter

2016-09-20T21:24:33+00:00

The cpu_has_counter macro indicates whether the current CPU has a
working coprocessor 0 count & compare registers, and has no bearing on
the GIC. Stop checking it.

Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: Daniel Lezcano 
Link: http://lkml.kernel.org/r/20160913165644.627-2-paul.burton@imgtec.com
Signed-off-by: Thomas Gleixner

clocksource/mips-gic-timer: Print an error if IRQ setup fails

2016-09-20T21:24:33+00:00

We've checked for errors from setup_irq_percpu since commit f95ac8558b88
("CLOCKSOURCE: mips-gic: Add missing error returns checks") but didn't
print an error message in the failure case. This makes it very easy to
overlook the GIC timer clock event driver not being registered, since
we'll generally just use a different clock event driver if that happens.

Print an error if IRQ setup fails in order to make such problems harder
to miss (ie. not completely silent).

Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: Daniel Lezcano 
Link: http://lkml.kernel.org/r/20160913165644.627-1-paul.burton@imgtec.com
Signed-off-by: Thomas Gleixner

clocksource/drivers/mips-gic-timer: Make gic_clocksource_of_init() return int

2016-08-17T11:08:32+00:00

In commit:

  d8152bf85d2c0 ("clocksource/drivers/mips-gic-timer: Convert init function to return error")

several return values were added to a void function resulting in the following warnings:

 clocksource/mips-gic-timer.c: In function 'gic_clocksource_of_init':
 clocksource/mips-gic-timer.c:175:3: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c:183:4: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c:190:3: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c:195:3: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c:200:3: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c:211:2: warning: 'return' with a value, in function returning void [enabled by default]
 clocksource/mips-gic-timer.c: At top level:
 clocksource/mips-gic-timer.c:213:1: warning: comparison of distinct pointer types lacks a cast [enabled by default]
 clocksource/mips-gic-timer.c: In function 'gic_clocksource_of_init':
 clocksource/mips-gic-timer.c:183:18: warning: ignoring return value of 'PTR_ERR', declared with attribute warn_unused_result [-Wunused-result]

Given that the addition of the return values was intentional, it seems
that the conversion of the containing function from void to int was
simply overlooked.

Signed-off-by: Paul Gortmaker 
Signed-off-by: Daniel Lezcano 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-mips@linux-mips.org
Fixes: d8152bf85d2c ("clocksource/drivers/mips-gic-timer: Convert init function to return error")
Link: http://lkml.kernel.org/r/1471429296-9053-3-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar

clocksource/mips-gic: Convert to hotplug state machine

2016-07-15T08:40:26+00:00

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran 
Signed-off-by: Anna-Maria Gleixner 
Reviewed-by: Sebastian Andrzej Siewior 
Cc: Daniel Lezcano 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.380737946@linutronix.de
Signed-off-by: Ingo Molnar

clocksources: Switch back to the clksrc table

2016-06-28T08:19:35+00:00

All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of

Signed-off-by: Daniel Lezcano 

For exynos_mct and samsung_pwm_timer:
Acked-by: Krzysztof Kozlowski 

For arch/arc:
Acked-by: Vineet Gupta 

For mediatek driver:
Acked-by: Matthias Brugger 

For the Rockchip-part
Acked-by: Heiko Stuebner 

For STi :
Acked-by: Patrice Chotard 

For the mps2-timer.c and versatile.c changes:
Acked-by: Liviu Dudau 

For the OXNAS part :
Acked-by: Neil Armstrong 

For LPC32xx driver:
Acked-by: Sylvain Lemieux 

For Broadcom Kona timer change:
Acked-by: Ray Jui 

For Sun4i and Sun5i:
Acked-by: Chen-Yu Tsai 

For Meson6:
Acked-by: Carlo Caione 

For Keystone:
Acked-by: Santosh Shilimkar 

For NPS:
Acked-by: Noam Camus 

For bcm2835:
Acked-by: Eric Anholt

clocksource/drivers/mips-gic-timer: Convert init function to return error

2016-06-28T08:19:24+00:00

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.

Signed-off-by: Daniel Lezcano

MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()

2015-11-11T07:36:41+00:00

Add user-mode implementations of gettimeofday() and clock_gettime() to
the VDSO. This is currently usable with 2 clocksources: the CP0 count
register, which is accessible to user-mode via RDHWR on R2 and later
cores, or the MIPS Global Interrupt Controller (GIC) timer, which
provides a "user-mode visible" section containing a mirror of its
counter registers. This section must be mapped into user memory, which
is done below the VDSO data page.

When a supported clocksource is not in use, the VDSO functions will
return -ENOSYS, which causes libc to fall back on the standard syscall
path.

When support for neither of these clocksources is compiled into the
kernel at all, the VDSO still provides clock_gettime(), as the coarse
realtime/monotonic clocks can still be implemented. However,
gettimeofday() is not provided in this case as nothing can be done
without a suitable clocksource. This causes the symbol lookup to fail
in libc and it will then always use the standard syscall path.

This patch includes a workaround for a bug in QEMU which results in
RDHWR on the CP0 count register always returning a constant (incorrect)
value. A fix for this has been submitted, and the workaround can be
removed after the fix has been in stable releases for a reasonable
amount of time.

A simple performance test which calls gettimeofday() 1000 times in a
loop and calculates the average execution time gives the following
results on a Malta + I6400 (running at 20MHz):

 - Syscall:    ~31000 ns
 - VDSO (GIC): ~15000 ns
 - VDSO (CP0): ~9500 ns

[markos.chandras@imgtec.com:
- Minor code re-arrangements in order for mappings to be made
in the order they appear to the process' address space.
- Move do_{monotonic, realtime} outside of the MIPS_CLOCK_VSYSCALL ifdef
- Use gic_get_usm_range so we can do the GIC mapping in the
arch/mips/kernel/vdso instead of the GIC irqchip driver]

Signed-off-by: Alex Smith 
Signed-off-by: Markos Chandras 
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11338/
Signed-off-by: Ralf Baechle